mocha browser runner is 10-100x slower than jasmine on equivalent suites #763
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CC @shtylman in case he has ideas or is interested in implementing such a change in node-process's |
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yeah we could certainly combine a bunch of the ticks, it hasn't bothered me much yet personally since we have small test suites for all the components but this would be great to improve |
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Yeah, I'd love to see this fixed, as there are a lot of cases where there's a big test case and performance is more important than small stack traces. Maybe make this configurable? |
This roughly doubles browser performance. Still far behind Jasmine however. mochajs#763.
This roughly doubles performance again. Plus, the scrolling is plain annoying.
This doubles performance again. Firefox should fix its damn bug (mochajs#757).
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Converted this to a pull-request that gets mocha to ~2-3x slower than Jasmine via low-hanging fruit. The slow part now is the DOM manipulation in the HTML reporter. |
tj
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mocha browser runner is 10-100x slower than jasmine on equivalent suites
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thanks man! |
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@jfirebaugh John, you are the man! 👍 |
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So @tmcw and I were petitioning to convert Leaflet's test suite to mocha and @mourner brought it to our attention that the result ran ten times slower (2s with mocha vs 0.2s with Jasmine).
I reproduced a similar slowdown in a simple benchmark which does nothing but execute 500 examples. Jasmine does it in about 0.1s, Mocha 3s.
I suspect Mocha is hitting a wall due to the latency of window.postMessage used by the
process.nextTickimplementation. Replacing this implementation with synchronous execution offnleads to a sizable performance improvement (but of course regresses #153).I guess to improve this mocha will need a nextTick worker queue and some manual scheduling logic, so that multiple ticks can run in each setTimeout/postMessage "timeslice".